Surface Treatment of Stainless Steel 304 Flanges

Stainless steel 304 flanges are a vital component in various industrial applications. These flanges are made from an alloy that contains chromium and nickel, which gives them excellent corrosion resistance properties. They are widely used in industries such as oil and gas, chemical, petrochemical, and food processing. One of the key advantages of stainless steel 304 flanges is their durability. They can withstand high temperatures and pressures without losing their structural integrity. This makes them suitable for use in demanding environments where other materials may fail. Another important feature of these flanges is their versatility. Stainless steel 304 flanges come in different sizes, shapes, and types to meet specific application requirements. They can be easily welded or bolted onto pipes or equipment, providing a secure connection that prevents leakage. Furthermore, stainless steel 304 flanges offer excellent hygiene properties, making them ideal for use in the food processing industry. They are easy to clean and maintain, ensuring that the final product remains uncontaminated.
 
Today, I am going to talk about surface treatment and maintenance of stainless steel 304 flanges. Some issues need to be paid attention to when maintaining stainless steel 304 flanges. Stainless steel flanges that have been used for a long time should be inspected regularly. The exposed processing surface must be kept clean. The dirt should be removed, and the flange should be stored neatly in a ventilated and dry place. Stacking or outdoor storage is strictly prohibited. Always keep the stainless steel flange dry and ventilated. Keep the holder clean and tidy, and store it according to accurate storage methods. During installation, the stainless steel flange can be directly installed on the pipeline according to the connection method and location of use.
 
Under normal circumstances, the stainless steel 304 flange can be installed at any position in the pipeline, but it needs to be easy to operate and inspect. Please pay attention to that the medium flow direction of the globe valve stainless steel flange should be from the bottom to the top of the longitudinal valve disc. The stainless steel flange can only be installed horizontally. When installing stainless steel flanges, pay attention to the sealing performance to prevent leakage and affect the normal operation of the pipeline. Because stainless steel has good corrosion resistance, it allows structural components to permanently maintain the integrity of their engineering design. Corrosion, pit, rust or wear doesn’t happen for stainless steel flanges. Chromium-containing stainless steel flanges also combine mechanical strength and good elongation, and are easy to process, which can meet the needs of architects and structural designers.
 
All metals react with oxygen in the atmosphere to form an oxide film on the surface. If holes are formed, the surface of the carbon steel can be protected by electroplating with paint or oxidation-resistant metal. However, as we all know, this protection is only a thin film. A stainless steel 304 flange is to fix two pipes, pipe fittings or equipment on a flange plate; add a gasket between the two flange plates, and fasten them together with bolts to complete the connection.
 
Some pipe fittings and equipment already come with flanges, which are also flange connections. Stainless steel flanges include threaded flanges and welding flanges. It is a disc-shaped part and is the most common in pipeline engineering. Flanges are used in pairs. In pipeline engineering, flanges are mainly used for the connection of pipelines. In the pipelines that need to be connected, a flange can be installed. 
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Commonly used surface treatment for stainless steel 304 flanges
1. Surface whitening treatment
2. Surface mirror bright treatment
3. Surface coloring treatment
Surface whitening treatment: During the processing of stainless steel flanges, a black oxide scale is produced after rolling, edging, welding or artificial surface heating.
This hard gray-black oxide scale is mainly composed of two EO4 components, NiCr2O4 and NiF. In the past, hydrofluoric acid and nitric acid were generally used to remove it by strong corrosion. However, this method costs a lot, pollutes the environment, is harmful to the human body, and is highly corrosive, so it is gradually being eliminated.
 
There are currently two main methods for treating oxide scale, which are as follows:
1. Shot blasting: mainly uses the method of spraying micro glass beads to remove the black oxide scale on the surface.
2. Chemical methods: Use a pollution-free pickling passivation paste and a normal temperature non-toxic cleaning solution with inorganic additives for immersion to achieve the purpose of whitening the original color of the stainless steel flange. After processing, it has a dull color. This method is more suitable for large and complex products. Stainless steel flange surface mirror brightening treatment: Depending on the complexity of the stainless steel flange and user requirements, mechanical polishing, chemical polishing, electrochemical polishing and other methods can be used to achieve mirror gloss.
 
The advantages and disadvantages of these three methods are as follows: 
Surface coloring treatment: Stainless steel flange coloring not only makes stainless steel flange have various colors, increases the variety of designs and colors of the products, but also improves the wear resistance and corrosion resistance of the products.